Administration of powdered medicaments by inhalation is frequently carried out with dry powder delivery devices (DPIs). In conventional DPIs, the powdered medicament is held in either manually-loaded single-dose capsules or blisters, which must be pierced, punctured or opened to release the dose, or a large multi-dose powder reservoir within the device from which medicament is dispensed by manually actuating a dosing and dispensing mechanism.
WO 98/26828 and WO 03/051439 disclose several delivery devices for use with medicament containers that have openings through which medicament is dispensed within the delivery device. The delivery devices all comprise a mouthpiece in fluid communication with a chamber, in which the medicament container is located. The chamber itself is in direct fluid communication with the exterior of the device via air inlet means. In use, air is drawn into the chamber through the air inlet means, which generates motion of the medicament container in the chamber, causing medicament to be dispensed from the container and entrained within the air flow, such that the airflow with entrained medicament is inhaled through the mouthpiece. The disclosed delivery devices include single-use devices pre-loaded with a medicament container and multi-use devices in which medicament containers may be inserted into the chamber before or between uses.
The delivery devices disclosed in WO 98/26828 and WO 03/051439 represent a considerable advance over the prior art, but may nonetheless be further improved.